Photographic film.



lF. w. LovEloY.

PHOTOGRAPHIC FILM.

APPLICATION msn APR. s. 1918.

Patented Aug. 13, 1918.

IN V EN TOR.

www yf TTOR/VEY unirnn srnrns FRANK W. LOVEJOY, 0F ROCHESTER, NEW YORK.

PHOTOGRAPHIC FILM.

Application filed April 8, 1918.

T0 all 'whom t may concern:

Be it known that I, FRANK W. LovnJoY, a citizen of the United States of America, residing at Rochester, in the county of Monroe and State of New York, have invent-ed certain new and useful Improvements in Photographic Films, of which the followlng is a full, clear, and exact specification.

This invention relates to photographic film and more particularly to sheets of such film associated with backing strips 1n cartridges, packs and similar articles of manufacture, The principal object of my invention is to provide the fllm adjacent each section to be exposed (commonly called a picture area) with a latent identifying symbol which corresponds to a printed mark on the backing strip, such latent symbol developing during the normal ,treatment of the film into a uniformly neat and legible means of identification.

In the accompanying drawing:

Figure 1 is a. perspective view, parts being broken away, of a partially unrolled lm cartridge embodying my invention, certain latent invisible symbols being diagrammatically indicated by visible characters;

Fig. 2 is a plan view of a Elm pack unit embodying my invention;

Figs. 3 and 6 are diagrammatic views of pieces of developed film resulting from my invention;

Figs. 4; and 5 are longitudinal sectional views of two species of stretched roll film elements in which my invention may be em bodied.

After roll films and film packs have been developed, it is very desirable to identify each of the negative views appearing in the various picture areas thereof. In order to accomplish this result conveniently, the photographer should know at the time of exposure which of the picture areas he is using for that particular view and should also be able to recognize that same area after development. The identification of the picture area at the time of exposure is generally made by means of printed numbers on the backing strips in the case of roll films and on the pulling tabs in the case of film packs. But the backing strips or paper tabs become separated from the film during development and subsequent fluid treatment, so that the diiferent picture areas can no longer be identified. The photographer at the time of exposure may have noted, for

Specification of Letters Patent.

Patented Aug. 13, 1918.

serial No. 227,404.

instance, that the views on areas 8, 9 and 10, show statues of lVashington, Jefferson, and Franklin, respectively; but after the backing is removed he cannot readily tell which areas are 8, 9 and l0 and so cannot identify or distinguish between the negative views of the confusingly similar statues.

I have found that this difficulty of identiiication can be overcome and the necessary data supplied by providing in or adjacent each picture area a latent image of a nu` meral corresponding to the numeral on the backing paper or tab which identifies that area. These latent images develop into neat legible numerals during the regular treatment of the films so that each view is clearly ident-ilied by its number. For instance, if the photographer noted, when taking the pictures, that the views on areas 8 9 and 10 showed statues of Washington, Jeerson, and Franklin respectively, he can, after de velopment, differentiate between these similar views by reading the developed identifying numeral thereon.

These latent images of the numerals are printed on the film by the manufacturer, preferably using machines which light print the characters uniformly to just the right extent called for by the characteristics of that particular sensitive film. The article of manufacture, such as a roll film cartridge or film pack, is thus sold to the consumer complete with coperating numerals on the backing paper and film, the first visible the other invisible but developable. This prepared article makes unnecessary any complicated numbering mechanism in the `ca1nera itself, which mechanism, if it depends upon light from a picture-taking exposure, .is sure to fail when deep shadows in the subject cause insutlicient light to reach it in the camera.

Referring now to the examples of my invention in the drawing, I have shown at l a conventional flanged spool upon which are wound a sheet of film Q, and a strip of backing paper 3. The latter may be joined by connecting strips 4, while the lilm has at one end a leader 5. The backing paper may have a sticker-band 6 thereon. A sheet 7 of material for receiving inscriptions, such as carbon transfer' paper, may be located between flm 2 and backing paper 3, as shown in Fig. 5.

Upon the outerside of the backing paper are sets of printed consecutive numerals S which are successively visible in the camera l to identify the picture areas of film 2 in the Well known vvay. Along' the medial line ofY the film are a series of latent light-printedv images 9 of numerals corresponding to numerals-8 and so locatedas to come adja-` cent tliepicture areas Which they identify after development. Of c'ourse,'these latent images are invisible Vuntil development but have been shown diagrammatically in theA drawing by double-line numerals for con- Y venience.

i After development, Vthese numerals appear as black clear figures; thus-in Fig.' 3 developed numerals 10 identify theadjacent picture areas 11. These numerals may moreover be located` along the edge of the lm instead of between the views and may be located adjacent an inscription space 12, as shown in Fig. 5, so that identifying symbols Will Y automatically develop adjacent each view Whether or not the photographer makes an inscription onthe film. @r the numeral may supplement the inscription.

In Fig. 2 I have Vshown a film pack unit or element in which arbacking strip 13, hav-V ingV a pulling tab 14, is attached to a ffilm sheet 15. The tab has visible numerals 16 printed thereon, While. the sheet carries a latent image 17 of acorre'sponding numeral.

Copiesof this patent may be obtained for ve cents each, fby"addressing Washingtoml). C. Y

l/Vhile I prefer to use numerals as the cooperating visible and latent characters in myV improved article of manufacture, any other Yconvenient identifying symbols may be used.

Moreover the position of the latent images of the numerals is not vital so longas they serve to conveniently identify the picture areas When developed.

l/Vhat I claim is 1. As an article of manufacture, a sensi-V tive photographic film sheet having an area thereon to receive a picture, and a backing strip for said film, said backing strip having a visible symbol thereon for identifying said area7 and said film sheet having therein adjacent said area a latent developable symbol corresponding to said visible symbol on said strip. f

2. As an Varticle of manufacture a sensitive photographic lm sheet having areas to' the lGommissoner of Patents, 

